This specification relates to fault detection and location isolation in pulsed systems such as pulse amplitude modulated (PAM) communication systems and optical time domain reflectometers (OTDR).
Telecommunication lines, such as digital subscriber lines (DSLs), may include sections of wires that have been joined together to form a data path from one location to another. A point where two sections of a telecommunication line are joined is referred to as a “splice.” In forming a splice, the end of one section may be wrapped around or otherwise joined to the end of another section. The two joined ends may be soldered to prevent the splice from becoming loose or crimped with Scotch Lock connectors or crimped to a 710 connector or similar cable splicing device.
It is generally desirable for a splice to remain in a tightly joined position to reduce the resistivity of the splice. However, a splice may become degraded (e.g., loose) over time. In such a case, the resistivity of the splice may fluctuate, which may disrupt communications occurring over the telecommunication line that includes the faulty splice. In an optical system, the fault may be a fiber break or a crimping of the fiber resulting in degraded performance or complete loss of communication.